Studying Cannabis on Campus, Pt. 1

A new study in the March, 2017 issue of the journal Addictive Behaviors takes a look at “College Student Marijuana Involvement” through an examination of “perceptions, use, and consequences across 11 college campuses” by Matthew Pearson, Bruce, Liese, and Robert Dvorak.

This is a valuable and well-designed study based on interviews with over 8,000 students at 11 universities located throughout the United States, though it does have some sampling flaws which suggest caution in interpreting its results. Simply put, these results are not based on a randomly selected representative sample of college students, but instead, despite the number of students surveyed and the broad selection of schools, it’s what is known as a convenience sample.

The authors selected schools in 11 states with a variety of marijuana policies in place, two from legalization states (Colorado and Washington), four from state with medical marijuana laws (New Mexico, New York, Wyoming and California) and five others (Alabama, Virginia, North Dakota, Texas and Kansas).

Students were recruited form psychology department participant pools at Colorado State, the University of Washington, the University of New Mexico, the University of Buffalo, the University of Wyoming, UCLA, Auburn, Old Dominion University, North Dakota State, the University of Houston and Kansas University. The sample was about 65 percent white, 12 percent black, and 18 percent Hispanic, as well as 67 percent female (a feature of the psychology department participant pools).

Overall, 53 percent of the survey pool had used marijuana at least once in their lifetime, and 26 percent were past month marijuana users. Also, 45 percent of the sample were freshman, 22 percent were sophomores, 18 percent were juniors and 14 percent were seniors.

One of the primary purposes of the study was to examine the consequences of marijuana use, and a close look at the data reveals little of great concern.

But it depends on how the data is described. The problem here, the language problem, concerns what is grouped into this category labeled as “consequences.” For example, the opening discussion of this article cites a 2014 article by Nora Volkow, director of the National Institute on Drug Abuse during the Obama administration, and colleagues published in the New England Journal of Medicine which, as described by Pearson et al in this article, reported that: “The long-term consequences of heavy marijuana use (especially in younger populations) may include addiction, altered brain development, poor educational outcome, increased likelihood of school dropout, cognitive impairment, lower IQ, diminished life satisfaction, and lower achievement.”

However, the findings of Pearson et al, while described as evidence of “negative consequences”, are quite different than those claimed in the Volkow article. So, take a close look at this key paragraph about the negative consequences of marijuana use among the college students in this study:

“The most commonly endorsed consequences were
driving a car while high (49.2%),
saying or doing embarrassing things (45%),
using on nights when planned not to use (44.9%), and
feeling in a fog, sluggish, tired or dazed the morning after use (44.7%).

The use of marijuana while driving, or before driving, is problematic at best. It’s just not a good or safe idea, and it is something that can and should be addressed through public education campaigns and appropriate legal sanctions.

Otherwise, the most serious “consequences” listed here are experienced by a very small percentage of college students. All of them are issues of concern; none of them can be attributed solely to cannabis use.

It’s one thing to conclude that college students who use marijuana experience negative consequences, but when those are itemized, the innuendo that marijuana use is dangerous is clearly unsupported by the data.

The authors of this study recognize this, and note that “These results highlight the importance of distinguishing between non-problematic and problematic marijuana use.”

Most importantly, the authors recommend development of guidelines for establishing the safe use of marijuana, observing that as yet “there is little empirically-based guidance regarding safe use of marijuana,” and that while “the illicit status of marijuana may have delayed the development of such guidelines, the increasing number of legal marijuana markets highlights the importance of developing such guidelines.”